In the decades since 1863, when the British geologist Robert Bruce Foote discovered the archaeological site of Attirampakkam 60 km from Chennai, multiple excavations have thrown up the oldest known stone tools in India, belonging to the Acheulian industry, characterised by bifacial handles and cleavers, and other chopping tools.
Last week, a study in Nature reported evidence from Attirampakkam that suggests early humans may have left Africa much earlier than has been believed so far — a potential breakthrough in our understanding of the evolution of the human species. The Middle Paleolithic Culture in India has traditionally been dated to around 1,25,000 years ago. The new study, however, says the “processes signifying the end of the Acheulian Culture and the emergence of a Middle Palaeolithic Culture occurred at 3,85,000 years ago and continued at Attirampakkam until 1,72,000 years ago”.
The Middle Paleolithic Culture is significant, since it is associated with modern humans. The new research also challenges the view that modern humans brought these technologies to India less than 1,40,000 years ago, say researchers. The study is based on 7,200 stone artefacts collected from the site soon after fresh excavations began in 1999. The study, however, is clear that “conclusive correlations between the Middle Palaeolithic assemblages at ATM (Attirampakkam) and a specific hominin species —whether modern humans or archaic hominins — cannot be established because India currently lacks fossil or genetic evidence for this time period other than the Narmada fossil cranium, which could signal the late survival of an archaic species”.
Study co-author Shanti Pappu of the Chennai-based Sharma Centre for Heritage Education said discoveries made at the site “mark a shift in the way Acheulian people made their tools. The first phase had shown us a combination of tools, and in the later phase we can see that there is more development going on.” Pappu said one of her colleagues used luminescence dating to question the evidence on when early man was moving out of Africa. “Now our data shows this might have happened even earlier… The question is, who made these tools? And the answer is, we don’t know… We don’t have hominin samples in India.”
The discovery in 1982 of the fossilised remains of a human cranium in the Narmada Valley remains the only bit of evidence available in the Indian subcontinent to support the ‘Out of Africa’ theory. “The environment in India is such that there are no organic remains,” said Ashok Singhvi of the Physical Research Laboratory in Ahmedabad, who carried out the luminescence dating to figure out the age of the fossils.
He explained that a technique called the infrared-stimulated luminescent that identified the last time sediment grains were exposed to light, showed the tools were between 3,85,000 and 1,72,000 years old. There are two implications of this, Singhvi said. “Firstly, when did the main man come out of Africa. If we believe the ‘Out of Africa’ hypothesis, then he must have come much earlier. Also, were people evolving in different places, able to produce the same technology at the same time?
“Secondly, if man came from Africa, how and when did he spread out so rapidly? We need to look at more sites in India, and the journey in between. The whole story will take many years to uncover. We are constantly getting new evidence from other sites, in places like Jordon and Morocco. We need to wait for some time to better understand how humans evolved.”